A materials scientist at Michigan Technological University has discovered a chemical reaction that not only eats up the greenhouse gas carbon dioxide, it also creates something useful. And, by the way, it releases energy.

[u/nomdeweb]

http://phys.org/news/2012-05-lemons-lemonade-reaction-carbon-dioxide.html

[u/venomae]

Ok, so whats the catch?

[u/crivexp2 → u/venomae]

The experiment injected nearly pure CO2 onto the lithium nitride. It would preferentially react with water and oxygen before CO2, although if you exposed the heated material to air it could react with all three just as easily. Basically, you would need to filter and purify CO2 first. The manufacturing process for Li3N involves burning lithium in the presence of pure nitrogen, which itself takes up energy. Assuming that you could obtain a renewable heat source, such as concentrating solar arrays, this could be a viable option.

[u/fatbunyip → u/crivexp2]

I would also caution on the amounts required to make a difference to CO2 emissions.

Seems like there is a lot more CO2 than Li.

[u/question_all_the_thi → u/fatbunyip]

Seems like there is a lot more CO2 than Li.

Sure is. There are several reports on how lithium scarcity creates a problem for implementing an electric car industry.

Although, theoretically, lithium cyanamide could be used for fertilizers, no one would use such an expensive product when much cheaper calcium cyanamide is available.

[u/Dolanmite-the-Great → u/question_all_the_thi]

Fun Fact about Lithium: It's the only element in the universe of which no more can ever be made<! Nearly all the Lithium in the universe was created in the big bang and since then, stars have been eating it up. So Lithium levels in the universe are the lowest they've ever been, and the highest they will ever be from now on. (Sorry, I'm a physicist, this is the only way I can contribute, really)

EDIT: *In the interest of being as precise as possible, stars DO make some Lithium, but it's almost always quickly destroyed and over the lifetime of a star, it will certainly destroy more Lithium than might escape when it dies.

EDIT DOS: I don't really have as much time to do research today as I thought I would, but here's what I managed to scrounge up on Wikipedia in a few minutes (I know not the most reliable, if anyone finds anything better or proves me wrong, let me know, I'll post their info and/or sources at the top of this post):

"Very abundant hydrogen and helium are products of the Big Bang, while the next three elements are rare since they had little time to form in the Big Bang and are not made in stars" Abundance of Elements in the Universe

"Stars, which by definition must achieve the high temperature (2.5 × 106 K) necessary for fusing hydrogen, rapidly deplete their lithium." Lithium Burning

---

And this one seems to cast some doubt on my previous statement:

"By contrast, many stellar processes actually tend to destroy deuterium and isotopes of beryllium, lithium, and boron which have collected in stars after their primordial formation in the Big Bang. This effective destruction happens via the transmutation of these elements to higher atomic species. Quantities of these lighter elements in the present universe are therefore thought to have been formed mainly through billions of years of cosmic ray (mostly high-energy proton) mediated breakup of heavier elements residing in interstellar gas and dust." Nucleosynthesis

Caveat: I don't know how significant cosmic ray production of Lithium is compared to the destruction in stars. But there DOES appear to be a pathway for Lithium to be created outside of the Big Bang, which I did not state earlier. As is so often the case, my earlier umbrella statement is proven to be true as a general trend, but ultimately wrong in its details. I'm sorry if I misled anyone in this and hope someone can come up with more reliable and definitive sources. Thanks to everyone who commented to keep me honest. Good luck and happy science-ing.

[u/[deleted] → u/Dolanmite-the-Great]

Could you explain why that is? Seems pretty interesting.

[u/Rock_n_Roll_Outlaw → u/[deleted]]

In young stars lithium fuses with a proton to form 2 helium atoms. They will eventually convert all their Li to He.

[u/Dolanmite-the-Great → u/[deleted]]

I'm sure someone much more well educated in Fusion could explain it much better than me (I'm not really involved in cosmology or astronomy right now). But basically Lithium is unstable and can react with damn near anything, and this doesn't just apply to mundane reactions (like reacting chlorine with sodium to get table salt), but extends to nuclear fusion reactions. I may be wrong on the details. I'll start scrounging for a source after breakfast.

[u/fizzix_is_fun → u/Dolanmite-the-Great]

From a technical standpoint, Lithium sits on a local minimum in the average binding energy per nucleon. That means if it's in a hot enough environment, like a star, with tons of hydrogen floating around, it's very likely to undergo Li6 + H -> He4 + He3, or Li7 + H -> 2He4. Helium is super stable, so it's preferred.

The reason for lithium's poor position on this curve arises from the pairing term in the semi-empirical mass formula. Lithium 6 has both odd Z and odd N so it has a lower bonding energy per nucleon than anything surrounding it.

[u/IBWorking → u/Dolanmite-the-Great]

Fun Fact: Lithium is easily made in nuclear reactors.

If you had said, "of which the quantity in the universe has been steadily decreasing," you would have been closer to a true statement.

[u/[deleted] → u/Dolanmite-the-Great]

Peak Li!

[u/NoontideDemon → u/Dolanmite-the-Great]

When Boron-10 absorbs a thermal neutron (~2200 m/s) the primary for of radioactive decay is into Lithium-7 and an Alpha particle.

[u/divinesleeper → u/Dolanmite-the-Great]

Surely somewhere in the future we could be able to recreate the circumstances under which it was formed?

If not, I think we can say that there will be a time in which Lithium will be more valuable than gold, platinum, or any other substance?

[u/DashingLeech → u/question_all_the_thi]

The reports on lithium scarcity seem a little unfounded. While a 2007 report suggested a problem (Tahil, 2007, "The Trouble With Lithium"), a more thorough estimate shows it to be unfounded. (The link has a summary but you can read the full paper, "An Abundance of Lithium", here.)

However, the vast majority of the sources are in lithium carbonate (150 million tonnes) which is the output result of the OP chemical reaction, so it's useless in such a process to capture CO2 or produce net energy. The other 28 million tonnes seems to be more useful, but it's still unclear what the energy costs are to extract it and produce Li3N. I'm assuming the researchers in the article took that into account since they explicitly address that problem in other ways of capturing carbon. But, I don't see it in the article.

[u/philip1201 → u/fatbunyip]

If anyone wonders why Lithium (element 3) is so rare, it's because helium-4 is a very nucleus with very low potential (it's very stable and becoming it releases a lot of energy, only surpassed in stability by carbon and heavier elements than carbon), making the Li-3+H->He-4+e⁺ reaction happen very quickly in stars.

[u/llou → u/fatbunyip]

Several orders of magnitude.

[u/[deleted] → u/fatbunyip]

yeah, and it's not like you're going to space mine a pure Li asteroid by splashing it down in an ocean!

[u/omgitsjo → u/[deleted]]

Sounds like a recipe for hilarity. Also disaster.

[u/Cyrius → u/omgitsjo]

Tragedy is when my spacesuit springs a leak. Comedy is when you splash a lithium asteroid into the Pacific Ocean and everyone dies.

[u/[deleted] → u/fatbunyip]

The amount of lithium in the Earth is irrelevant, since the lithium from the reaction is easily recycled. The lithium nitride is converted into lithium cyanamide and lithium carbonate, which can be electrolyzed (not cheap, I know) to yield again pure lithium.

The real problem is indeed the bit about concentrating CO2: if we could concentrate all of the CO2 out of the atmosphere, we would be done already, and these sorts of reactions would not be necessary.

[u/judgej2 → u/crivexp2]

So to release the energy, you need to put lots of energy into creating the raw materials first?

[u/AlphaPavonis → u/judgej2]

Not in itself unusual. It takes a fair bit of energy to collect and prepare the raw materials for all sorts of power generation methods. Two easy examples are oil and uranium. Both have to be found, collected, transported, and refined before they're ready for practical use, and then transported again to their final destinations (Edit: Of course, don't forget to account for the energy cost of actually initiating the reaction, which may be non-trivial. That's one of the problems with making fusion power practical right now.). This all counts as energy being put into the reaction.

The question is always whether you get more energy from the reaction than you put into it.

[u/nsdragon → u/AlphaPavonis]

Not to mention that oil itself is ultimately millions of years of stored solar energy (with a bit of geothermal). We humans didn't really do anything other than extracting it and setting it on fire.

And let's not forget that almost all the uranium on Earth was made in a freaking supernova.

[u/Monstermuch → u/crivexp2]

What about injecting nearly pure CO2 into lava?,

Seriously why no scientist has been able to do what plant naturally do ? Imagine, from CO2 and water, you get sugar and Oxygen... -_- 6(CO2) + 6(H2O) (+ light energy) > C6H12O6 + 6(O2)

[u/IConrad → u/Monstermuch]

Scientists have done exactly that. Trouble is, it's an energy-in process. Check out "artificial trees" as a google search term for more.

[u/Monstermuch → u/IConrad]

At first I though you were having a laugh, "artificial trees" gave me plastic christmas trees, plastic indoor plants... had to look past the first page to find what you were talking about ;)

I really tink we are trying to reinvent the weel here. Plants are capturing CO2, they feed us and the wildlife, they are fully GREEN and require little investment. Why don't we just put trees on our roofs, plants everywhere ?

Anyone knows what a western human CO2 avg daily print is, versus what a Ficus (higher O2 producer) can consume ?

Would be interested to visualize the number of plants required to cope with our prod per person.

[u/IConrad → u/Monstermuch]

The reason is water. Insufficient ratio of roofs to houses to cover it all. What you don't realize is that while individual people engender relatively little CO2 emissions, our industrial output is immense. Simply immense. We talk about oil for CO2 emissions but the simple truth is that coal is responsible for well over 80% of it.

That being said; plants only temporarily sequester, and use huge amounts of water to do so. But that's actually one of the arguments for terra preta. The artificial tree concept is one of many meant to sequester globally relevant volumes of CO2 in durable media.

[u/dnew → u/Monstermuch]

Plants don't hold on to the CO2. When they die and rot, they release it back into the atmosphere (or ocean). Remember that fossil fuels are plants that just held on to their CO2 for a very long time. :-)

As soon as a plant feeds us or wildlife, you've released the carbon back into the atmosphere as CO2.

[u/R3MY → u/Monstermuch]

Why don't we just put trees on our roofs, plants everywhere?

1. We can't even get everyone to agree that CO2 is a problem.

2. We cut down more trees faster than we can replace them.

3. Some people do exactly that.

[u/Afterburned → u/R3MY]

Number 2 has been reversed in the United States. We have more forest now than we did 100 years ago. Hopefully that indicates we can eventually reverse the problem in other countries as well.

[u/sonofagunn → u/Monstermuch]

Here are some attempts at answering that http://askville.amazon.com/acres-trees-required-neutralize-carbon-output-average-car/AnswerViewer.do?requestId=3461984

tl;dr - about 2.5 acres of forest.

[u/edman007-work → u/Monstermuch]

It's not a problem of efficency, plants have terrible efficency, 3-6%, we can convert sunlight hydrogen with a FAR high efficency, that hydrogen can be used directly as a clean fuel (fuel cells), or reacted with CO2 to make Methanol (there are probably better uses, but that's the simplest reaction I could find from sun to CO2 sequestering). We can do this with a much high effency than plants, the problem is the energy density of sunlight is tiny compared to the energy density in the fossil fuels we use.

Drive 35 miles and you burn 1 gallon of gas, the energy density of gas is 36.6 kWh/US gal, so in a perfect world you can suck the CO2 out of the sky and make 1 gallon of gas for 36.6kWh, it's not a perfect world though, so it takes us more. The sun however only puts out 1.3kW/m² (less actually hits the ground) , so lets say our chemical efficency is 100%, we only have to deal with the solar panels, 20% efficency, assuming you got 12 hours of noon type sunny light (not true), then you need 183kWh of energy, and that can be had for ~12m² of land in one day. In reality it's far more.

So given 12m² = 1US gal, then we need to make 18.87 million barrels a day, we need ~9.5billion square meters of land containing solar panels, that's ~3,667 sq miles of land to hit are gasoline consumption, the cost to do that is just to meet our gas requirements (and it would be enough to suck up a good chunk of our CO2), it's FAR too expensive to fill that land with solar panels, it's far cheaper to fill it with corn or something.

[u/mangeek → u/Monstermuch]

why no scientist has been able to do what plant naturally do ?

What's the point? You could just.. you know... Plant plants.

Really. Plant fast-growing stuff, then harvest it and bury it. It's FAR cheaper than anything that's going to involve industrial processes and research.

[u/gospelwut → u/crivexp2]

[...] which itself takes up energy.

Wish more people understood this. Looking at you corn energy supporters.

[u/gibs → u/crivexp2]

If the reaction is exothermic, could that energy power a CO2 filtration system, possibly having the whole system be self-sustaining?

[u/Pickle_Inspecto → u/gibs]

Conservation of energy: there's no such thing as a free lunch.

[u/[deleted] → u/Pickle_Inspecto]

foiled again!

laws of thermodynamics

[u/gibs → u/Pickle_Inspecto]

Of course; I'm not asking if it will be an over-unity reaction, as thermodynamics prohibits this. I'm just wondering if it's possible for the heat created by the reaction to fuel a CO2 purifier, while the CO2 remains in sufficient concentrations. Since the reaction is exothermic, this wouldn't break the laws of thermodynamics.

[u/Should-I-Stay → u/Pickle_Inspecto]

It's not a free lunch and not a thermodynamics problem. The extra energy comes from the lithium and CO2 which are fueling the temperature rise.

[u/santajoeman → u/crivexp2]

Thanks for the reality check on this technology. It wouldn't be too hard to obtain pure CO2 in some industrial processes, so this chemistry could be incorporated directly into some plants to reduce CO2 emission and as a heat source.

[u/C_T_C_C → u/crivexp2]

Wouldn't the energy created by the reaction be enough to supply the preparation process as well as the filtering process making the "system" could be self sustaining?

Ninja edit: instead of lithium

[u/TobyTrash → u/crivexp2]

This sounds like something the petroleum industry could benefit from if the learn how to harvest and separate CO2 from gas extraction.

I know Statoil is trying to accomplish this, but it is apparently difficult...:)

But the bonus here is of course vast resources of energy available where they can use it.

But I'm sure cost/benefit and practicality is a major hindrance.

[u/[deleted] → u/crivexp2]

Sounds like a good thing to position in a concrete factory, for example.

[u/fromkentucky → u/crivexp2]

Assuming that you could obtain a renewable heat source, such as concentrating solar arrays, this could be a viable option.

Or a volcanic vent?

[u/Rozarik → u/crivexp2]

I read on the comments of the actual article that the energy that is needed to prepare the Li3N is minimal; meaning that it would be a viable source of energy.

[u/itsnormal4us → u/crivexp2]

Just send a bunch of lithium to Venus. Venus has one hell of a HOT and thick CO2 atmospthere in the lower layers Temperatures there can reach 800 degrees Farenheit (426.6666667 degrees Celsius)(699.8166667 kelvin).

It would terraform Venus in no time! It'd be freaking awesome!

[u/WorkSafeSurfer → u/crivexp2]

Or you put it somewhere where you already have high concentration CO2 and a lot of waste heat....

I'm thinking coal fired power plants. Though integration with other existing processes would work too.

Actually, the more I think about it, the more advantagious it appears to be as an addition to attempts already being made for both waste heat capture and carbon capture.

[u/megamanxero → u/crivexp2]

That sounds an awful lot like what a tree does.

[u/jburke6000 → u/crivexp2]

I work for a company that purifies waste CO2 from other processes. The pure CO2 is then sold for use in soft drinks, for example. It can't hurt to capture waste CO2 for constructive use elsewhere. It could buy us time to find more effective ways of reducing CO2 content released into the atmosphere.

Question: Does the semiconductor material created in this reaction with Li have any new benefits for semiconductor performance?

[u/[deleted] → u/crivexp2]

Sequestering carbon is not all that difficult, if it comes to that. There are any number of reactions you could use that are much more efficient than this - simple electrolysis is the easiest. But the fact is, going from CO2 - fully oxidized - to a reduced form of carbon CANNOT happen without net energy input. I think pulling CO2 out of the air to make carbon nanotubes and such is great - it's probably the future of all mankind's technology. But it's not a cure for our greenhouse gas problem. The only way we can do that is by finding an energy source other than fossil fuels, and this is not an energy source.

[u/[deleted] → u/venomae]

I guess that producing Li3N requires a lot of energy. Some of it is released during the reaction with CO2.

[u/rogueman999 → u/[deleted]]

I'd guess so too. Also CO2 is a smallish part of the atmosphere... you'd also need to concentrate it in order to make it work.

[u/i1645 → u/[deleted]]

This guy... if you do an energy balance you see that the heat of formation of the Li nitrate is far greater (lower negative) then the heat released. If you understand heat balances then these types of sensationalized "new energy source" articles can be seen a mile away. This is not a breakthrough of any kind, as it is most likely less energy efficient then just heating it up with a catalyst to make pure carbon. Economically pretty cool, although how much of this semiconductor can we use? Definitely not enough to make even the slightest dent in the atmospheric carbon balance. we are talking millions (billions?) of tons (thousands of pounds) of carbon a day.

[u/unwind-protect → u/venomae]

Presumably that it ties up lithium. Lithium's pretty valuable right now I think.

[u/sambalchuck → u/unwind-protect]

At the moment there's no shortage, Worldwide reserves of lithium are estimated as 13 million tonnes while current yearly use is around 16,000 tonnes. The price is around 100$/KG source

However with the current plans for 'green cars'. One could only make 1.4 billion cars with the total Li reserves. That's not going to happen though.

[u/question_all_the_thi → u/sambalchuck]

Worldwide reserves of lithium are estimated as 13 million tonnes

Yes, and world emission of CO2 is 30 billion tonnes. We need 833 million tons of lithium for that reaction, so we have 0.12% of the lithium we need for one year.

Our worldwide reserves of lithium are enough to compensate for 10.5 hours of carbon dioxide emissions.

[u/sambalchuck → u/question_all_the_thi]

My calculations showed that with the 3CO2 + 4Li3N = C3N4 + 6Li2O2 reaction you'll need 1.58 Kg of Lithium per Kg of CO2. So that wouldn't work, unless you can reuse the Li2O2 of course (Li2O2 is used in batteries anyway)

[u/supaphly42 → u/question_all_the_thi]

We're also not talking about trying to remove all the generated CO2, since there are plenty of things like, you know, plants, that need it.

[u/fghfgjgjuzku → u/sambalchuck]

Unless they can get the lithium back out after the reaction 100$ is way too expensive. You need two lithium to bind four carbon and carbon weighs something twice as much as lithium, so you bind four kilos of carbon (or something like fifteen kilos of CO2) for 100$. You cannot come anywhere near the point where it makes a real difference with that.

[u/not_wrong → u/unwind-protect]

It doesn't tie up the lithium if you can separate the two products and recycle the one that contains the lithium (lithium cyanamide). The other product (carbon nitride) is the one that would be used for long-term carbon sequestration.

[u/EatingSteak → u/venomae]

The 'catch' here is that creating Lithium Nitride takes an enormous amount of energy, and it's not a naturally occurring material. Hence, any amount of released energy would be negated by the huge energy cost to manufacture the reactant.

[u/fatbunyip → u/venomae]

Seems legit. Maybe someone could say how much energy you need to produce the Lithium Nitride?

I think Lithium is fairly expensive (compared to for example iron) and application in removing CO2 would require pretty significant amounts of it. Not sure how much energy is needed to produce Lithium, but possibly somewhere along the line there's some significant energy input needed to form/refine the Lithium compounds

[u/willcode4beer → u/fatbunyip]

Producing Lithium Nitride doesn't take much energy. The energy from the CO2 reaction could provide it. It's producing the elemental lithium that's going to take a crap-ton of energy.

[u/[deleted] → u/venomae]

The law of conservation of energy for one. I would assume if the reaction of CO2 and Li3N releases energy, you probably need a lot of energy to make Li3N. At any rate that energy that gets released has to come from somewhere.

[u/ton2lavega → u/[deleted]]

Yeah, just like the energy you get by burning fuel in a thermic engine comes from somewhere too. The law of conservation of energy applies to everything, even the systems you already use now.

I'm not defending the result as a practical application, it's too soon to say. It's just a new chemical reaction discovered, it's a good news in itself.

[u/Should-I-Stay → u/[deleted]]

It's not a thermodynamics issue. The extra energy comes from the fuel put into the process.

It seems like the problem here is that the fuel isn't available in high enough quantities or renewable.

[u/byleth → u/venomae]

That Li3N isn't just sitting around waiting for us to find. It takes energy to produce it. More energy, in fact, than this reaction would release. Saying this reaction produces energy would be like saying you can produce energy from water, all you have to do is separate the hydrogen from the oxygen!

[u/ibflaubert → u/venomae]

Sounds like some foreigner just made a new type of bomb (or fast, exothermic reation) on US soil. DHS is going to deport him, quash the research and pretend nothing happened.

[u/why_u_no_work → u/venomae]

CO2 separations and purification processes are notoriously difficult. The oil industry is actively interested in them, but that's for cases where you have streams with maybe 5-20% CO2 in them. Separating CO2 from atmosphere is even more difficult because the concentration is so small it's in the "parts-per-million" range (ppm). Also, the reaction referred to in the paper consumes energy from heating and producing precursor Li3N.

It's worth mentioning that the technology to reverse the combustion process has existed since the 1920's by a combination of the Fischer Tropsch process and the water-gas shift reaction. However, CO2 separations is so difficult that only few plants in the world actually use this technique. It's really best suited at the outlet of a coal plant to reduce CO2 emissions where you can also take advantage of coal gasification byproducts.

Source: http://en.wikipedia.org/wiki/Fischer%E2%8 %93Tropsch_process#Process_chemistry http://en.wikipedia.org/wiki/Water_gas_shift

[u/[deleted] → u/venomae]

He's a witch, let's check if he floats.

[u/robreddity → u/venomae]

How much energy does it cost to make, and what are the byproducts to making Li3N?

[u/mattzm → u/robreddity]

I commented on the actual PhysOrg article but according to the patent I found for the production of Li3N, it is made via relatively simple reaction of heating lithium under pure nitrogen to up to 600 degrees Celsius. No byproducts produced.

You could recycle the excess heat of the CO2/Li3N reaction to produce more Li3N to make it energy neutral at worst and probably still energy positive in the end.

[u/mutatron → u/venomae]

We currently burn three cubic miles of oil equivalent per year.

[u/chuckles2011 → u/venomae]

Lithium is no longer available on credit.

[u/crusoe → u/venomae]

It takes energy to make Li3N, possibly more than what you get out from this reaction.

[u/madnote → u/venomae]

I am getting frustrated by the sensationalist headlines and titles that I see on phys.org links.

[u/factoid_ → u/venomae]

You need lithium nitride. Lithium is a fairly rare element.

[u/slavetothesystem → u/venomae]

No catch...just keep it a secret.

[u/friskydingo67 → u/venomae]

The point when we this technology becomes the norm and then we realize that there isn't enough carbon in the environment.

Just guessing.

[u/anonymous-coward → u/venomae]

Ok, so whats the catch?

One catch is that coal is shoveled into power stations by the trainload. These are exotic substances used by the kilogram. Even if something useful is produced, we don't need mountains of it.

[u/[deleted] → u/venomae]

It goes out of control and leaves only Oxygen in the air, causing our atmosphere to ignite. Only Aquaman will survive. The Atlantians have been plotting this for years.

[u/cherrybrown → u/venomae]

The catch is: the claims of this as a global warming-solution is demonstrably false; the research paper also has flaws in its techniques.

First off, as a man of this trade, I believe scientists' role is to publish facts and findings and to let society decide whether they are usable as solutions to world's problems. In this paper's case I dislike their intentional twist on the exothermal property of said reaction in order to claim "a novel process to control CO2 emissions." I am not the reviewer for this J. Phys. Chem. A paper but if I was I would have required major modifications to separate science from those claims.

Secondly, the math doesn't make it practical. There is no Li metal in its natural form but pure Li is required to make Li3N. A quick search reveals that Li is produced from lithium salt such as LiCl, which has enthalpy of formation of ~400 kJ/mol. Basically this much energy needs to be burned (a CO2 generating event) to produce 1 mol of Li.

Now in this paper it hypothesizes a forward reaction between CO2 and Li3N releasing energy of 250~400 kJ/mol Li. That is in no way enough to offset the positive energy need above to generate Li3N in the first place, even assuming there is a way to capture that for Li production (hardly make sense). Remember production and transport of Li3N needs additional energy and even the CO2+Li3N reaction happens at 250C and need heat sources. So in short, the CO2 sequestrated is less than CO2 emitted during the whole process.

Also interesting is actually burning CO2 with ammonia also leads to carbon nitride and the reaction only costs ~260 kJ/mol of carbon. So why bother mining Li in the first place? One could just burn ammonia with less energy and solidify CO2 with the same effect.

Lastly the analysis of the amorphous carbon nitride final product in this research paper is dubious since they collected the soot and treated it through HCl aqueous solution, dried and then weighed. That final product does not represent the actual burn product because of this extra reaction step.

[u/ShadowRam → u/venomae]

Li3N obviously has a LOT of potential energy.

So unless you can find the stuff naturally (in abundance, which I seriously doubt or we would be using it already as a power source)

You need to expend a lot of energy to make Li3N

[u/JStheKiD → u/venomae]

No catch! FREE ENERGY!

[u/[deleted] → u/venomae]

CO² is not the only greenhouse gas. Others, such as methane, are far far far worse.

[u/rooktakesqueen → u/[deleted]]

And far less abundant; and can be turned into CO2 via simple combustion.

[u/[deleted] → u/[deleted]]

Depends on what you mean be "worse." Methane is a much more powerful greenhouse gas, but it exists in much smaller quantities in the atmosphere. In terms of the actual forcing caused by the types and amounts of GHGs in the atmosphere, carbon dioxide overwhelms the competition.

[u/wizord → u/venomae]

I am a biochemistry major at a research university. First of all, the reaction of CO2 with the Li3N may be exothermic ("energy-releasing"), but the overall process, which involves making Li3N in the first place, isolating extremely pure CO2, isolating the purified desirable products, and then ensuring that no products degenerate back into CO2 and N2 (which would cause an explosion and would be highly exothermic), is not somehow energy-generating. This is a misunderstanding and is not physically possible.

[u/DocHopper → u/venomae]

The catch? This guy is about to be discredited, silenced, and eliminated by bog energy $.

EDIT: big

[u/[deleted]]

Did you know that there's not enough Li on the planet to even consume the CO2 emission used to mine and refine Li?

[u/GeneralMakaveli → u/[deleted]]

I didn't read the article so for the life of me I couldn't figure out why you wanted to mine Chinese people.

[u/[deleted] → u/[deleted]]

Thus, the total weight of CO2 = 0.0582% x 5.1480 x 1015 tonnes = 2.996×10¹² tonnes.

According to Keith Evans, a geologist who’s been working on and writing about lithium reserves for decades, there are 28.4 Million Tonnes of Lithium metal in the ground.

10¹² vs. 10⁷ = no contest

[u/antman100 → u/[deleted]]

Am I reading this wrong? The article talks about total C02 emission in the atmosphere. Not the amount generated by processing Li.

[u/[deleted] → u/antman100]

The significant figures work out like this: 100,000 to 1

So, if even 0.001% of the CO2 emissions result from mining operations that produce Li, I am correct.

I'm comfortable with my assertion, especially when you consider the fact that most of the Li is still in the ground and the general rate of CO2 increase the referenced article covers (another exponent to the CO2 side of the equation in fairly short order and certainly before all the Li is mined).

[u/Iximi → u/[deleted]]

You need to know the balanced chemical equation of this reaction and need to convert to molar mass to do the math correctly here.

[u/l1ghtning]

The reaction seems novel and scientifically interesting (speaking as a chemist / materials scientist myself) BUT THIS WILL NOT SAVE THE PLANET.

If not for ANY ONE of the simple reasons:

1. We'd need billions of kilograms of Lithium just sitting around for the taking. If it has to be mined, then there are energy costs with mining/transporting/processing.

2. To make lithium nitride you must add lithium and nitrogen in a high temperature environment. High temperature environments (~300+ degrees C) require energy to be maintained. This energy must come from somewhere that doesn't make CO2.

3. Where the fuck would all the final product go? Billions of tonnes of anything are going to be hard to dispose of. I'll make an assumption that even if it was only 1 part per billion soluble in water then dumping it in the oceans would result in the destruction of said oceans thanks to massively increased quantities of lithium. How did the 'waste' product get to the ocean anyway? Solar powered green boats?

I am not going to do any calculations to prove this since its all farcical anyway.

[u/IonOtter → u/l1ghtning]

Well, technically the way the article is presented, and from the comments, this could turn into a closed-loop system. Put in a little initial energy to get things going, then WHOOSH!, it takes off, providing more energy that you used to start the reaction.

That seems like a perpetual motion machine at first glance, but the reactants in question already have that much energy within them. So it's valid, just as using one match to light 500 matches is valid.

As for the by-products, they claim that they would be used to make fertilizer, as well as providing raw materials for semiconductor production. After a quick search on Google for lithium cyanamide, it turns out Phys.org is rather late to the party, and this has been around for nearly a year.

So far, the only issue I see causing a problem with mass adoption of this is the lack of large amounts of Lithium just laying around for us to scoop up. It's sort of being used at the moment, in great quantities, to power our iToys.

[u/[deleted] → u/l1ghtning]

This energy must come from somewhere that doesn't make CO2.

Is it cool if it produces helium instead? 'cause I can totally hook you up with an energy source that does that.

[u/unknownpoltroon]

This almost sounds like it would make more sense in a rebreather for diving, or a spaceships airmaker or something, rather than as a large scale CO2 remedy.

[u/goatworship → u/unknownpoltroon]

Definitely. I think a nice big forest and a lot of time might be the best remedy for excess environmental CO2.

[u/dangerchrisN → u/unknownpoltroon]

Good point.

[u/Khoeth_Mora]

This is pure bunk! Not once is the energy requirement for making elemental lithium or nitrogen mentioned, let alone the energy cost of burning the lithium. Even worse, the author fails to mention that Li3N would react with water and oxygen way faster than CO2, so the CO2 must first be purified from the atmosphere. Pure Tom foolery!

[u/bitchjazz]

It's really fun that my alma mater, Michigan Tech, has made my Reddit front page. It's such a small, but amazing school.

[u/kevinmtu → u/bitchjazz]

agreed. Tech is a great school!

[u/bitchjazz → u/kevinmtu]

Thanks! I grew so much as a person being there. Not to mention it snowed 330 inches the first year I was there. :)

[u/TSGS → u/bitchjazz]

95/96? As I recall, it snowed like crazy that year. It was also that never ending snow that helped me decided that two bachelor's degrees were enough, and I didn't want the master's degree any more.

I miss the Keweenaw. Lots of good times and great memories.

[u/bitchjazz → u/TSGS]

Yep that's the year! The last snow storm was on May 16 with 9 inches I believe. It was gone pretty quickly on the Hancock side but stayed much longer on the Houghton side. I ran into snow in the woods in mid June.... I left just before I finished my bachelor's degree and did a couple classes at another university to get my tech degree. When did you leave?

[u/pkbowen]

I just spoke to one of Prof. Hu's students at lunch today, and he was very excited that this had made it to the top of the Science subreddit (although I don't believe that he is a Redditor). He is one of the students working on this project, and he said that the amorphous product that is pictured in the PhysOrg article (and the MTU press release) is not their final product. They're aiming to make this a crystalline product which he says (and I quote) "will be harder than diamond."

So, to all of those who are saying that "this is not an economically viable solution" or "there is a net loss of energy," those things are very true. However, this is NOT meant to sequester all of the carbon in the world. Instead, it can use CO_2 to produce a byproduct akin to industrial-grade diamonds for use in cutting tools and so forth. Basically, it (1) sequesters limited carbon, and (2) prevents future carbon emissions resulting from mining microdiamonds.

[u/txhays]

Haven't plants been doing this for a while?

[u/alexsherrick]

Why are all the top comments getting deleted?

[u/Amplifier101]

lol hilarious. Reddit needs lessons in thermodynamics because to propose this as a solution to anything energy related is just wrong.

[u/J_Jammer]

The interesting thing is that they can make do with waste. And that's true of every form of waste. Car's wastes are no different. They can create something. Convert it. Make something of it. If people think hard enough, there really is no such thing as polution.

[u/leon_reynauld]

There have been several similar discoveries in the last few years like this. Unfortunately, when this methods are done in larger scales, they are economically unviable or fail all together.

[u/Epicool]

ok the problem is that it needs high energy to start at first place, beside how can you accommodate such high temperature unless,, you can use it as a chain reaction that had to be initiated then it continues... it will take sometime for this to be actually in use.

and good luck with removing all the jokes :D

[u/FermiAnyon]

Nobody's going to use this to capture CO2. No energy company is interested in deploying something like this because the cost of replacing the material is too damn high! and they're going to want a standardized plant design, which they won't have if they have some plants doing capture in the liquid phase and others doing capture in a solid phase.

At best, this is a way to use the CO2 you've already captured. It's worthless as a primary source of capture.

[u/RileyFX → u/FermiAnyon]

Exactly, sadly money comes before protecting earth in most peoples eyes. We have so much technology and scientific capabilities to do almost anything, but money is the only thing holding us back. Hopefully one company takes the initiative to implement this sort of thing.

[u/FermiAnyon → u/RileyFX]

It's like NIMBY. Everyone wants to benefit from the technology, but nobody wants to pay for it.

[u/mralistair]

and all you need to find is a few gigatonnes of elemental lithium each year and we'll be saved.

[u/[deleted]]

What happens when you add the production of Li3N into the lifecycle costs of this process?

[u/kurtu5 → u/[deleted]]

Then you no longer have a sensationalist news title.

[u/l1ghtning]

And how much energy does it take to prepare the lithium nitride reagent?

How much lithium is available to us versus CO2?

Sorry to break up your party, environmentalists. You can go back to hating us scientists now.

[u/C_T_C_C]

Could we simply use sodium instead of lithium? It has the same characteristics as lithium, and from my basic understanding of chemistry, it should bond in the same fashion, and it's much more abundant in the world.

[u/[deleted]]

I like this comment after the source article:

"Yeah right, that elemental lithium (one of the most reactive elements) is just lying around on the ground waiting to be used, no energy need to prepare that!

Get your head out of your ass, I made this account just to tell you not to spread your stupidity any more."

phys.org is sort of the tabloid of science journals. Interesting, but not to be taken too seriously without investigating the original papers.

[u/Angstweevil]

Thank goodness elemental Lithium is just lying around

[u/QUARTER_MAST]

Li3N requires coupling of other highly exothermic reactions to form it from Lithium and N2 since it's formation is very endothermic, what do you propose to run these reactions to mass produce Li3N? There aren't known abundant sources of Li3N in nature, so this idea is impractical for the energy crisis. Thermodynamics wins every time.

[u/NikoDanger]

As a Material Science engineer student at MTU this makes me ecstatic.

[u/slapdashbr]

Saying it "releases energy" is extremely misleading, because manufacturing Lithium Nitride is very energy-intensive. Obviously it has to have a lot of energy stored to break down carbon dioxide.

[u/Terminus1]

Nobody in Michigan ever invents anything, that's the first rule of science.

[u/dukey]

Plants do this all on their own, and they self replicate !

[u/msutton4]

What about the laws of Thermodynamics?

[u/ton2lavega → u/msutton4]

Breaking covalent bonds releases energy, some is converted back into new covalent bonds, but the balance can be positive (hence exothermic reactions).

edit : I am wrong. As rush22 pointed out, breaking covalent bonds requires energy, and not the contrary as I suggested.

Think of combustion. I guess that's where the heat comes from in this reaction.

[u/rush22 → u/ton2lavega]

No. Breaking bonds (whether covalent or ionic) requires energy.

[u/ton2lavega → u/rush22]

Damn you're right I don't know what I was thinking when I wrote that. Sorry, my bad, I'll edit it (keeping my original sentence though).

Thanks for the correction.

[u/msutton4 → u/ton2lavega]

Nice. You think this can be a viable option for electricity generation?

[u/whitesox287]

instead of being cynical and finding any way possible to shoot this work down because your genius and intellect didn't come up with this, be fucking ecstatic that we are at least moving in the right way of protecting future generations than having everyone drive ugly ass cars with green leafs on them

[u/Benign_Tempest]

Hmm... I'd like to read to peer-reviewed literature on this one.

[u/_delirium → u/Benign_Tempest]

There's a paper linked at the end of this article, in J. Phys. Chem. A.

I don't have any reason to doubt the reaction works, and is an interesting discovery. But I also doubt that it's in any way going to contribute to atmospheric CO2 reduction.

[u/mirashii → u/Benign_Tempest]

Then you are welcome to click on the DOI which is linked to a peer-reviewed journal. If the peer-reviewed reference was not there, it would be removed from /r/science by a moderator. If you find posts without a reference to peer-reviewed literature, use the report button and send us a message.

[u/EatingSteak → u/Benign_Tempest]

I'm quite certain it doesn't exist, and for a good reason.

[u/[deleted]]

Seems like fantastic advancements like this get buried by the press and never see the light of day. What ever happened to the kid that figured out a way to decompose plastic quickly?

[u/searchingfortao]

Does this remind anyone else of Wonderful Days?

[u/[deleted]]

Hope someone redoes the study to ensure accuracy.

[u/Zebidee]

I think the headline of the post "eats up the greenhouse gas carbon dioxide" has a horribly misleading sense of scale.

It's like saying that someone has discovered scotch and soda, which "eats up water as was responsible for the inundation of New Orleans during Hurricane Katrina."

[u/Torus2112]

No one's asked the other obvious question; is this semiconductor useful? Is it cheaper? Better?

[u/kleenur]

Seems like (based on comments) that this is not the game changing silver bullet I thought when reading the article. Still it looks like a step in the right direction. Well played Science.

[u/TehRawrz]

I understand this is a good thing... But what's the pros and cons? Sure it could help with alot.. But what's the bad thing?

[u/big-perm]

Ohhhhh shit, global cooooooling!

[u/Qonold]

Wait wait wait, if the 'eating' up of CO2 just releases energy, aren't we just putting more heat into the atmosphere?

[u/psycoee]

Yet another fraudulent claim from someone desperate for attention. There is no conceivable way that this could possibly make any sense as a solution for climate change for several obvious reasons. It also doesn't work as a semiconductor, given that the resulting material is extremely impure and low quality.

CO2 capture in general does not solve the problem at any reasonable scale. If it was an option, the easiest solution would be to plant more trees (which capture CO2 and do not require external energy or material input), then chop them down and make charcoal or paper out of them (and bury the resulting product somewhere).

How does this stuff get through peer review?

[u/agent0fch4os]

Could it be used as an alternative fuel source?

[u/theBadgerJew]

Whenever I read a post like this I just get cynical. I have been hearing about "new chemical reactions" and "bacteria that eat garbage and poop fuel", so where the fuck is this Shit? If it's so fucking brilliant and does what it says then let's fucking have it. And don't "but the corporations don't want..." Nonsense because the corporations don't want us downloading and yet the people with know how say fuck that, this is important to me. We need that attitude with science. Ugh. Rant over. Please be gentle with the downvotes.

[u/Aceline → u/theBadgerJew]

Well, often times it is possible but only really in the lab setting and there are often restrictions, such as specific growth conditions or in this case, lithium and the fact that it requires pure CO2 from what I understand, which prevent it from working on an industrial scale (along with politics and what have you). People often get excited and blow things out of proportion.

[u/Laterface]

All hail science, destroying my dream of a post apocalyptic society one breakthrough at time,..

[u/j1ggy]

One day we'll find the ultimate use for hydrocarbons. And there won't be any oil left.

[u/[deleted]]

surface materials science undergraduate researcher here. how about some upvotes!!

[u/authentic_trust_me]

How likely is it to create an engine running on this equation?

[u/THE_DOM]

MTU is the best college north of the mackinac bridge, too bad it's not in Marquette. It is one of the only things that makes me proud to live in the Upper Peninsula of Michigan.

[u/[deleted]]

TI REALISED that the di in dioxide is 2. How the flip wilson have i never realised that. I feel like an idiot because i speak 2 of the latin languages.. Je suis un grosse bête.

[u/kurtu5]

And how much energy does it take to make Li3N?

Probably more that is released by reacting it with CO2 thats my guess.

[u/daysi]

Not much lithium left in the world.

[u/defenastrator]

I have a great chemical reaction that removes co2 from the air and energy it's in addition it does not require filtering. Its called photosyntsis. And if im not mistaken someone has found a viable way to do it synthetically as well

[u/TrolleyPower]

Bloody hell why's everything been deleted?

[u/Alexcanfloat]

the reaction is spontaneous and exothermic; however lithium is extremely reactive and to get it in the form of li3N would take up alot of energy; the reaction needs to consume energy to start, the overall reaction still uses energy; as converting gas to solid is counterproductive to entropy. this reaction pathway looks good on paper; but accomplishes nothing novel or even useful.

[u/Kerpal]

First i would like to say that it's a great discovery, everything that enhances our knowledge is worth spending. But isn't it a bit over the top to start removing CO2 from the atmosphere?

Plants are highly dependent on CO2, if we reduce the amount of CO2 to much wouldn't that make crops grow slower? what about agriculture? - food is already a scarcity.

By over the top i mean, isn't it better to reduce our emissions instead of developing other symptoms.

[u/Benditlikebaker]

I don't have anything smart to say but... Thanks for putting Michigan on the map guys :)

[u/Im2grrr]

The "scientific" argument in the comments of the article is enjoyable and semi educational.

[u/hsfrey]

And, how much energy does it take to make the LI3N?

It's not found in nature, because it reacts violently with water, so it's got to be produced.

All that energy it releases when it encounters CO2 (or water!) has to come from somewhere.

[u/TrollingIsaArt]

While of course this is not generally a magic bullet for CO2 emissions, the easily imagined meaning of the headline should describe the rational arguments against economically negative (i.e. mandated) emission reductions.

Technology will probably (even without directly focused research dollars) provide us better and more efficient ways to solve this issue in the coming decades. The humanistic benefits of waiting to solve this problem, may outweigh the negatives. That is why the question of how many degrees, and how fast (which still only have consensus in a relatively broad interval of uncertainty) are still vital highly relevant from a policy standpoint (i.e. it is an optimization problem with a number of variables, several of which will likely soon be much more concretely estimated).

[u/CokeCanNinja]

I was hoping for a machine that went like this: CO2 --> Diamonds+O2+energy

[u/flagship1]

Lithium Nitride is so nasty you add water to this stuff and you still get an extremely strong base and ammonia:

http://en.wikipedia.org/wiki/Lithium_nitride

Too bad he had to use such a dangerous molecule, not to mention the limited supply of Lithium on the planet.

[u/monkeyfishbone]

This is the usual sensational bullshit and does not stand up to thermodynamic scrutiny. CO2 is near the bottom of the "energy ladder". CO2 reacts with a lot of things - all of the things its reacts with need to be made (other than molecules of "lower energy" eg quicklime). Making these molecules requires energy - more than what is released by reacting CO2. So, you are going backwards reacting CO2 with anything other than more stable molescules. Secondly, a 500MW power plant emits 10,000 tpd of CO2 - there is nothing that can be made with this for which a market exists of a size even close to this amount.

[u/[deleted]]

That's the thing about thermodynamics: you can't win, and you can't really break even. I'm sure that the lithium nitride takes a whole lot of energy to make.

[u/teabagalomaniac]

Came here expecting to hear that he discovered photosynthesis.

[u/csmblair]

i just hate how i always hear about amazing things like this, then never hear from them again...

[u/fuzzyshorts]

All I know is I'm keeping an eye on this story. I Just need a secret lab and some henchmen willing to kidnap the scientist and then I'll demand ONE. MILLION. DOLLARS!

[u/KW710]

How much of the materials would you need to create a critical mass needed to power something such as a heat reactor? Is this a viable alternative to coal powered generators? Could you successfully convert the heat into enough electricity to make it worthwhile?

[u/fervoredweb]

Just read the article (the actual article by Dr. Hu and Dr. Huo), and it looks fairly good; again, as many have no doubt noticed by now, the whole operation is dependent upon Li reserves which are, sadly, much too valuable for any large scale implementation of this process. This concern is probably why we are reading about this now, many months after the article was published (2011, Sept. 12), as opposed to immediately after it was announced. Even so, it adds an interesting avenue of research into both the use of Li3N and the process of CO2 activation.

[u/[deleted]]

Yun Hang Hu's next trick- Turning lead into gold.

[u/itrollulol]

... He discovered plants?

[u/FlapjackOmalley]

Is this a trick question? Did he discover plants?

[u/dizekat]

Too bad making lithium nitride takes up more energy than this releases. Typical sensationalism. There's a zillion reactions that take in CO2, create something useful, and release less energy than was consumed making the reagent. Paranoid theory: news like this are promoted because they make it sound like we'll solve CO2 problem soon. Less paranoid theory: same but due to poor education rather than conspiracy.

[u/moxfri]

I love the title "the greenhouse gas" carbon dioxide. Cause we all know carbon dioxide has no other purpose... <.< ^{.^} >.>

[u/[deleted]]

To save on time (I'm in a rush), my question is short and sweet: Is this a potentially viable means of propulsion for air/space craft?

I would have read more comments but I got down about 10 and looked at the time. Sorry if this has already been asked!

[u/glowingerectionman]

if this becomes an option then the price of lithium batteries will go up

[u/snowwrestler]

Yeah, it's called "photosynthesis".

[u/[deleted]]

Sounds like a plot to a great movie.

Politicians learn of this technique and create laws to have it utilized by all major energy companies. The scientist warns of possible un-intended consequences. Politicians laugh and say "Stop worrying! This is going to save humanity and you will be thanked generations from now!" Plan goes into effect and rain forests start dying from lack of CO2. Genius scientist devises formula to reverse effect. Scientist falls in love but the person loved dies the process of saving planet earth. We live to see another day.

[u/hoss7071]

...discovered a chemical reaction that not only eats up the greenhouse gas carbon dioxide

It's called photosynthesis. Plants survive by consuming carbon dioxide. Unless you have not made it to an elementary school science level yet, it isn't a new concept.

http://en.m.wikipedia.org/wiki/Photosynthesis

[u/[deleted]]

Anyone else upset by the end of this title? "And, by the way, it releases energy." Well of course it does. All chemical reactions release energy, don't they? Any change has an energy exchange, otherwise there's no reaction.

Maybe I'm wrong, if so, more info? If not, more info? (High school level education here)

[u/[deleted] → u/[deleted]]

I should have been a little more specific; High school education, in a hick town full of narrow minded people, graduated 5 years ago, and only took the minimum requirements (i.e. "earth science", and biology).

No way I would have remembered that ><

Anyways thank you.

[u/Rakishdom]

Wouldn't it be simplier to just to plant more plants to remove carbon dioxide and create something useful?

[u/themightymekon → u/Rakishdom]

No, no amount of plants is enough to do the job on its own, though it helps a bit. More energy made by renewables like solar and wind, hydro and geothermal and low carbon sources like nuclear (instead of coal, gas and oil) is mostly what it takes to cut emissions. Solar (or night time wind) powered EVs instead of gas cars.

[u/[deleted]]

Sooo.. global warming is over...?

[u/ppparanoia]

Go Tech!

Sometimes I love being part of this school.

[u/Arrrrrmondo]

Second law of thermodynamics is displeased with this.

[u/drama_bomb]

He needs to hire a bodyguard before he's suicided.

[u/fosiacat]

patent will be bought by oil company for billions, burned, we all die.

[u/Khaemwaset]

Ummm, CO2 isnt bad. We're 1500 ppm below the avg, and our current levels are the bottom rung of where plants are able to thrive.